How to Test for Room Modes

Finding standing waves (room modes) in a listening space can be done fairly simply. Just hook up an audio oscillator to the audio console, editing or playback system, or use an internal oscillator if available, and send that signal out to one, and only one, of the full-range monitor loudspeakers.

Start with a frequency around 50-60 Hz, as this should be audible with a good quality monitor system. Start with a low level, and gradually raise the level if necessary. It doesn't need to be very loud.

Move around the room and listen. Sit in the mixer's and producer's positions and move your head or your chair back and forth and side to side. Keep listening to how the sound level changes.

While this may look like a moving meditation to someone from the outside looking in, as you go through this exercise you'll hear the sound level vary from a maximum (peak) at some positions in the room, to a null (no sound at all) in other places.

Repeat at different frequencies. The room modes will be most pronounced in the lower frequency range.

If the audio mixer or producer is situated where there are peaks or nulls, then consider making some changes.